1. Technical Field
Various embodiments of the present disclosure generally relate to an electronic device, and more particularly to a semiconductor memory device and an operating method thereof.
2. Related Art
Semiconductor devices may be manufactured as integrated circuits. Semiconductor memory devices are data storage devices implemented on the integrated circuit. The semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices.
The nonvolatile memory device can retain data stored therein even when power is shut off or interrupted. Therefore, the nonvolatile memory device may be used for the task of secondary storage, which does not lose the data when the device is powered down. Examples of the nonvolatile memory device include a Read Only Memory (ROM), a Mask ROM (MROM), a Programmable ROM (PROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a flash memory, a Phase change Random Access Memory (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM), a Ferroelectric RAM (FRAM), etc. The flash memory may be classified into a NOR type and a NAND type.
A memory cell array of the flash memory devices may have a two-dimensional structure in which memory cell strings are horizontally arranged on a semiconductor substrate. Alternatively, the memory cell array of the flash memory devices may have a three-dimensional structure in which the memory cell strings are vertically arranged on a semiconductor substrate.